Martial Pool - a New combat mechanic?

There have been so many developments in DnD over the last four or five years, I don’t know if this is new or not, but I thought it might spark an interesting discussion (and maybe I’ll find out if anyone else has done this). The Martial Pool is a system we have been using in our house rules for about four years now, it’s a new way of rolling combat dice for 3.5 OGL games. The system works like this. Each person gets a ‘pool’ of up to four twenty sided dice, they can roll each dice for individual attacks or what we call “active” defense, or they can combine two or more dice together for the same roll and only count the highest number.

We see this as a way to avoid the dreaded ‘flat curve’, as a sort of a sweet spot between the way a dice pool works and the twenty sided dice. You get the speed and reduced arithmetic of the former with the wide probability range of the latter, while still keeping the twenty sided dice we know and love in DnD.

How we got thereWe were running a gritty, low-magic campaign with an emphasis on martial arts and the tactics of fighting. We had made up our own neat little feats based on armed combat techniques from medieval fighting manuals we had. We were already using a defense roll with damage reduction like in D20 modern or Conan RPG, and we already had weapons rated for attack and defense, and had come up with some mechanics for bypassing armor. We felt that our combat system was enhanced over the standard system, but the back and forth still seemed a little too routine and mechanical especially in longer fights, and people kept getting really frustrated with the whole ‘flat curve’ thing with the 20 sided dice. I remember one of our players had just bought a new set of rather nice dice, he rolled a “1” on an important attack, and got so aggravated he threw the whole set of dice out the window and into the bushes in my back yard.

From our group of a bunch of gun nuts and sword nuts, we had different suggestions on how we could ‘take it to the next level’ with our combat system. We talked about Gurps, The Riddle of Steel, Burning Wheel, older games like Runequest and Rolemaster, the Grim and Gritty damage model, all sorts of other systems. We decided that we were more interested in the mechanics of the fight than on a complex damage model for our game. I personally felt tracking damage was simply too much accounting work, and frankly, since a lot of us were into martial arts we were more interested in who could cut the other guy first than rates of arterial bleeding or lung deflation. (maybe because in sparring, you never get to that part)

We looked at the dice pool mechanic from shadowrun, and tried out a few sessions of that game. We really liked how the dice pool seemed to be pretty fast and cut down on the headache of arithmetic somewhat. But we felt the range of probability from a six-sider or a ten-sider was too narrow, and changing the dice would be too much of a departure from DnD anyway. So we thought about a dice pool of twenty sided dice, but the dice pool itself was just too many dice to mess with, it quickly starts to get out of hand. Who wants to carry that many dice? And I didn’t really like playing with target numbers either once I started looking at how to make the stats work etc.

How it worksSo we came up with this ‘new’ idea. Why not keep the basic DnD mechanic of how the twenty sided die works, but only let the players roll two or more dice and take the best number? The idea occurred to us when we were rolling some characters, using that standard character generation method of rolling 4d6 and dropping the lowest die. Why not roll two or three d20s and drop your crappiest roll?

So we started thinking of how to implement this. I liked the idea of letting the player decide how to manage some of their dice for offense and some for defense, like in the Riddle of Steel and some other games. But that meant it would be quite likely that a player might run out of defensive dice. So we came up with the idea of passive defense.

Passive defense is like the armor class, except armor isn’t part of it. We give everybody a defense rating based on BAB, Dex bonus and the defensive value of their weapon. So passive defense is your defense rating plus 8. Active defense is defense rating plus your die roll. So effectively it’s a slightly higher average, plus to make this even more interesting, we decided that a natural 20 rolled on defense is automatically a counterattack. A tie when the defender meant you hit his weapon (if he had one) which leads to weapons being broken right and left. Makes maces more valuable than axes in certain respects.

This also fit well for attacks of opportunity. Instead of basic AoO on your Dex bonus, it’s based on your Martial Pool. If you have dice left, you can make an AoO, if you don’t you can’t. This gives you something else interesting to think about – do you use all your dice in attacks on that group of wolves or save some to keep one from rushing in to bowl you over? A feint could be modified so that it sucks away one of your martial pool points, so you could for example, feint at somebody, and if they fell for it, rush in to grapple range.

In fact we found this basic mechanic worked really well with all of our special “martial’ feats we had come up with. We were able to take away a lot of the arithmetic, +4 bonus to this or -4 to that, and play with the martial pool instead. It lent itself very well to all kinds of special circumstances which could give you a ‘free dice’, or an extra die for your pool – thus increasing your odds for a good die roll.

Bottom line, we have had a ball with this. It has made combat much more interesting for us and never routine. Some of the fighter characters occasionally fight duels over matters of honor now – to the first blood. Our wizards or the one guy who is holding off the enemy horde use all their dice for active defense. It lends itself to all kinds of drama. The desperate attempt to stab that soft spot in the dragons scales can be tried with a four dice attack.

To keep this managable, we made a rule on the die, fighters get 1 die in their pool per BAB, but it maxes out at four dice. This way the lower level mooks still only get their one die.

If you had a system which was even more combat oriented than ours, you could increase the ‘Martial Pool’ to a much higher number. We wanted to keep it fast.

Who might like itNot everybody would like this. If you are in a campaign where you are slaughtering orcs by the dozen, this could get a little tedious. I’m not sure how well it would work for a higher level campaign either, I think all of our testing was mostly done with mid level characters. It worked really well for us in our game, and beta testers of the new combat rules manual I wrote seemed to like it a lot, but they were mostly HEMA, escrima or Iaido people I knew through martial arts forums. I think quite a few people might also have fun with this idea, but definitely not everybody. A lot of people really aren’t interested in the mechanics of combat and many folks who play RPGs are really turned off by anything resembling realism. I think this is suitable for those few games where there is a heavy emphasis on tactics or realism or real cinematic combat as it seems to enhance drama somewhat.

I think this is a natural for Samurai based games, historically based games set in the middle ages or renaissance, or pirate / three musketeers type games. I also think certain gritty types of horror genre games like a lot of your Call of Cthulhu (Cthulhu Dark Ages?) type games might be suitable, where a fight is a fairly rare and deadly thing. It might be a good fit for high action zombie settings? I haven’t played many sci fi type settings in a long, long time but I think it could be really cool for a setting like the Matrix. It would probably be a lot of fun for a Star Wars setting. It might be good for some superheroes settings, I'm not sure.

And basically any games with an emphasis on martial arts or cinematic combat.

Interesting. In a way, your dice pool system is introducing a different "action economy".

You get 4 actions per round (each die roll representing one).
You can spend actions on attack, defense, opportunity attack or retry, but only one on attack and defense each.

(We might want to call this actions "active" actions - move actions are not part of the system - though they could be, especially in the 3E action model with full-round actions)

What do you think - is this a good alternative way to characterize your system? Or did I miss something?

Hi Mustrum,

Yeah I think that it a pretty fair way to characterize it. Two things to clarify:

1) is that we don't do re-rolls per se. The attacker and the defender have to decide how many they will roll before rolling. So this makes it sort of a gamble. You can't decide later after a miss (or after you were hit) to throw in another die, although you can always do a second or third attack if you have dice left in your pool.

We use the dice themselves as counters to show how much pool (or active action points, to use your term) that you have left.

2) you can do multiple attacks with this system. It can be riskier due to the potential of counter-attacks and the possibility of a natural 1 (which we rule is always automatically a fumble)

Of course that is just the way we do it, to date. I'm interested in seeing how other people might imagine it, maybe it would actually be better to limit to one attack and one defense.

The whole mechanic does make combat more lethal, at least in the system we use. It's much more dangerous to be ganged up on for example.

We have also experimented with letting people apply martial pool to saving throws and certain skill checks (like bluff or sense motive check for a feint) We have also experimented with incorporating movement into this too, charging 1 pool die for a move-equivalent action.

I've heard people mention action points but I've never used them, so I don't know, is that a similar concept?

Interesting. In a way, your dice pool system is introducing a different "action economy".

At a mechanics level Codex Martialis could be characterized this way but for me the main thing I get from it is choice. Choice in character development and choice in combat. With more choice in character development comes strategy -- developing the character over time to be more effective in combat. With choice in combat comes tactics -- working out how to effectively use your combat options with your companions to win a fight. If combat is your favourite part of the game then Codex Martialis is for you.

Yeah I think that it a pretty fair way to characterize it. Two things to clarify:

1) is that we don't do re-rolls per se. The attacker and the defender have to decide how many they will roll before rolling. So this makes it sort of a gamble. You can't decide later after a miss (or after you were hit) to throw in another die, although you can always do a second or third attack if you have dice left in your pool.

We use the dice themselves as counters to show how much pool (or active action points, to use your term) that you have left.

2) you can do multiple attacks with this system. It can be riskier due to the potential of counter-attacks and the possibility of a natural 1 (which we rule is always automatically a fumble)

Of course that is just the way we do it, to date. I'm interested in seeing how other people might imagine it, maybe it would actually be better to limit to one attack and one defense.

The whole mechanic does make combat more lethal, at least in the system we use. It's much more dangerous to be ganged up on for example.

We have also experimented with letting people apply martial pool to saving throws and certain skill checks (like bluff or sense motive check for a feint) We have also experimented with incorporating movement into this too, charging 1 pool die for a move-equivalent action.

I've heard people mention action points but I've never used them, so I don't know, is that a similar concept?

G.

Action Points work in different ways in different systems. D20 Modern and Eberron use them to gain a bonus (+1d6, at higher levels you may roll more then one die and select the highest). Both use a "regain only when leveling" approach and have mechanics to use them for different purposes (Artificers can cast infusions as a standard action for example). Arcana Evolved uses "Hero Points" and allows you to add +1d20 to a roll.
D&D 4E uses Action Points to get you an extra attack action (and certain abilities improve what you can do on them or are triggered with action points) Action Points are resetted each day and you gain them by reaching milestones. (basically, the more encounters you make per day, the more action points you will get - which can help you compensate loss of other resources)

Torg uses Possibilities to allow you improve your rolls. It uses a bonus chart for your d20 roll (so rolling a 1 causes a -8 penalty, rolling a 12 a +0 bonus, and rolling a 20 a +8 bonus) with diminishing returns at higher values (which can be only reached by getting rerolls).

There are many approaches to handle action point. The core idea seems always to be to introduce an extra resource that you can and have to manage. Some are more or less "tacked on" (D&D 3E, D20 Modern) - the system might work without them. Other systems (Torg) rely on them as the primary player resource (and in use overall they are strategic - the tactical resource in Torg are more the Drama Cards)

Its interesting enough to give it a buy. But why did you bunch the dice up at low level? Why not start at 2 dice + 1 die per iterative attack or something like that? And how could you apply this to skill checks and things like opening doors (D&D the only game where the the buff fighter and barbarian can't kick open a door, but the anemic mage can)?

Its interesting enough to give it a buy. But why did you bunch the dice up at low level? Why not start at 2 dice + 1 die per iterative attack or something like that?

I'm not certain what you mean but I'll take a stab at it.

We decided to keep the number of dice in the Martial Pool low to keep the system fast. You could have fun playing with larger number of dice but it could eventually slow down I think. If I understand what you mean by iterative attack, that would mean 3 dice at first level, 4 when you gain a second attack per round etc.? That might be a good alternative to our 1 dice per BAB with a cap, but I like the idea of 1st level / 1HD players having only one die because that keeps combat with low-level 'mooks' simple (you don't want to have to manage dice pools for ten orcs in a combat, or at any rate I don't).

The .pdf Kraftworks referred to includes a lot of other stuff besides this mechanic, particularly feats and different weapons stats which work with the idea of the martial pool a certain way.

But this Martial Pool idea could probably be adapted for a variety of game play paradigms, not just ours.

This idea was created (or more accurately, evolved) within a low magic, low-level system, under a philosophy kind of like something I saw mentioned in another thread on here called E6 (?). I suspect most of the beta testers of the PDF also used low magic / low level systems.

I think this could be adapted to higher level play, but the more you introduce magic into this the more you will have to consider. For example, a heroism potion or haste spell would seem a logical reason to boost your Martial Pool, wheras a slow spell might do the opposite. Or maybe it shouldn't involve the MP at all.

And how could you apply this to skill checks and things like opening doors (D&D the only game where the the buff fighter and barbarian can't kick open a door, but the anemic mage can)?

All we did so far with skill checks (and this is not in our PDF, just our house rules) was we allowed players to apply one of their Martial Pool dice to a skill check roll which was being done within a melee round, to improve the odds of their roll. So for example if our druid wanted to leap onto a table in the middle of a fight, I might let her use one MP die for her jump skill check. This would mean she would roll two dice, one she would get normally plus one from her pool, and keep the highest value. Then she would still have three dice left.

For movement and move-equivalent actions I just handled it by taking away one MP. So actually in the above example I might make her use one MP to jump on the table (i.e. just take it away as the price for a move equivalent action), then she elects to use another die for her skill check, and still has one left for active defense with her staff and another to attack with a nice thrust into the face of that pesky cultist chasing her.

I'm not certain if this is the best way to handle it or not it's just what we have been doing, it seems fun, the players like it. But there could be exploitable holes in handling it like that which I haven't thought of.

We decided to keep the number of dice in the Martial Pool low to keep the system fast. You could have fun playing with larger number of dice but it could eventually slow down I think...

That might be a good alternative to our 1 dice per BAB with a cap, but I like the idea of 1st level / 1HD players having only one die because that keeps combat with low-level 'mooks' simple...

I've found the balance in Codex to be very good. As Galloglaich points out, the system has to be fast to resolve in play. There's nothing worse than a ponderously slow combat system; it simply destroys the flow of the combat. Codex provides its tactical options without slowing the game.

Part of the speed-in-play issue is to ensure that the referee doesn't get bogged down managing the big fight scene. The "1 dice per BAB with a cap" mechanism ensures that the referee can control which of the NPCs has a Martial Pool to track. The mooks don't, streamlining the referee's management of the NPCs.

Originally Posted by Galloglaich

The .pdf Kraftworks referred to includes a lot of other stuff besides this mechanic, particularly feats and different weapons stats which work with the idea of the martial pool a certain way.

We decided to keep the number of dice in the Martial Pool low to keep the system fast. You could have fun playing with larger number of dice but it could eventually slow down I think. If I understand what you mean by iterative attack, that would mean 3 dice at first level, 4 when you gain a second attack per round etc.? That might be a good alternative to our 1 dice per BAB with a cap, but I like the idea of 1st level / 1HD players having only one die because that keeps combat with low-level 'mooks' simple (you don't want to have to manage dice pools for ten orcs in a combat, or at any rate I don't).

But this Martial Pool idea could probably be adapted for a variety of game play paradigms, not just ours.

This idea was created (or more accurately, evolved) within a low magic, low-level system, under a philosophy kind of like something I saw mentioned in another thread on here called E6 (?). I suspect most of the beta testers of the PDF also used low magic / low level systems.

You could always rule that PCs start with 2 dice and mooks start with 1 (just because PCs are special). Basically I just thought if you wanted to spread it out it would be for BAB +0 1 die, +1 to +5: 2 dice, +6 to +10: 3 dice, +11 to +15: 4 dice, +16 to +20: 5 dice. Then monks with Flurry of blows could gain +1 die for a -2 to hit, and +2 dice with an attack at 11th or higher level (you probably already do this, I haven't read that far into the document).